program BISHOPS;
const
  fi = 'bishops.in';
  fo = 'bishops.out';
  max = 10;
var
  w : array[1..max] of extended;
  n, k : longint;
  res : extended;

function count(k : longint) : extended;
begin

end;

procedure process;
var
  i : longint;
begin
  for i := 0 to k do w[i] := count(i);
  for i := 0 to k do res := res + w[i]*w[k-i];
end;

begin
  assign(input, fi); reset(input);
  assign(output, fo); rewrite(output);
  read(n, k);
  process;
  writeln(res:0:0);
  close(output);
  close(input);
end.